• Title/Summary/Keyword: continuous dependence

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Oxidative Decomposition of TCE over TiO2-Supported Metal Oxide Catalysts (TiO2에 담지된 금속 산화물 촉매상에서 TCE 산화분해반응)

  • Yang Won-Ho;Kim Moon-Hyeon
    • Journal of Environmental Science International
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    • v.15 no.3
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    • pp.221-227
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    • 2006
  • Oxidative TCE decomposition over $TiO_2$-supported single and complex metal oxide catalysts has been conducted using a continuous flow type fixed-bed reactor system. Different types of commercial $TiO_2$ were used for obtaining the supported catalysts via an incipient wetness technique. Among a variety of titanias and metal oxides used, a DT51D $TiO_2\;and\;CrO_x$ would be the respective promising support and active ingredient for the oxidative TCE decomposition. The $TiO_2-based\;CrO_x$ catalyst gave a significant dependence of the catalytic activity in TCE oxidation reaction on the metal loadings. The use of high $CrO_x$ contents for preparing $CrO_x/TiO_2$ catalysts might produce $Cr_2O_3$ crystallites on the surface of $TiO_2$, thereby decreasing catalytic performance in the oxidative decomposition at low reaction temperatures. Supported $CrO_x$-based bimetallic oxide systems offered a very useful approach to lower the $CrO_x$ amounts without any loss in their catalytic activity for the catalytic TCE oxidation and to minimize the formation of Cl-containing organic products in the course of the catalytic reaction.

Use Analysis and Evaluation of MEDLIS(MEDical Library Information System) Document Delivery Service (의학학술지종합정보시스템(MEDLIS)의 원문제공서비스 이용 분석과 평가)

  • Chang, Hye-Rhan;Kim, Jeong-A
    • Journal of the Korean Society for Library and Information Science
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    • v.46 no.3
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    • pp.233-250
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    • 2012
  • The purpose of this study is to assess the development, current states, and problems of MEDLIS document delivery service. With the analysis of MEDLIS transaction data from 2001 to 2011, we identified continuous usage decrease, unbalanced contribution by type of institution, high dependence on back issues, use differences among subfields of medicine, relatively low success rate, and various reasons for failure. Based on the results, recommendations for the maintenance of union catalog database, technical support for search capability enhancements, establishment of back issue archiving policy, user training and publicity, and membership expansion are suggested to promote the service.

Analysis of Surface Morphology and Optical Transmission Features in LB Films by SNOAM (SNOAM에 의한 LB막의 표면모폴로지 및 광투과상 해석)

  • Lee, Seung-Jun;Jung, Sang-Burm;Yoo, Seung-Yeop;Sin, Hun-Gyu;Park, Jae-Chul;Kwon, Young-Soo
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2000.04b
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    • pp.108-111
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    • 2000
  • We will illustrate the topographical structure and optical structure of the merocyanine dye LB films obtained by the scanning near-field optical/atomic force microscopy (SNOAM). SNOAM was recognized as a powerful tool to modify the surface as well as to characterize the topography of the surface at atomic resolution, especially for optical reaction materials. SNOAM images showed that the topographical and optical structures of these films were not only depended on the chemical property but also physical property. In the continuous measurement on these dyes, the appearance of near-field optical transmission images showed a certain dependence on the kinds of dyes and the mutual mixing ratios of dyes. These experimental results suggest that there is a certain kind of interaction between these two dyes.

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Changes of the Level of G Protein ${\alpha}-subunit$ mRNA by Withdrawal from Morphine and Butorphanol

  • Oh, Sei-Kwan
    • The Korean Journal of Physiology and Pharmacology
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    • v.4 no.4
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    • pp.291-299
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    • 2000
  • Morphine or butorphanol was continuously infused into cerebroventricle (i.c.v.) with the rate of $26\;nmol/{\mu}l/h$ for 3 days, and the withdrawal from opioid was rendered 7 hrs after the stopping of infusion. The expression of physical dependence produced by these opioids was evaluated by measuring the naloxone-precipitated withdrawal signs. The withdrawal signs produced in animals dependent on butorphanol (kappa opioid receptor agonist) were similar to those of morphine (mu opioid receptor agonist). Besides the behavioral modifications, opioid withdrawal affected G protein expression in the central nervous system. The G-protein ${\alpha}-subunit$ has been implicated in opioid tolerance and withdrawal. The effects of continuous infusion of morphine or butorphanol on the modulation of G protein ${\alpha}-subunit$ mRNA were investigated by using in situ hybridization study. In situ hybridization showed that the levels of $G\;{\alpha}s$ and $G\;{\alpha}i$ were changed during opioid withdrawal. Specifically, the level of $G\;{\alpha}s$ mRNA was decreased in the cortex and cerebellar granule layer during the morphine and butorphanol withdrawal. The level of $G\;{\alpha}i$ mRNA was decreased in the dentate gyrus and cerebellar granule layer during the morphine withdrawal. However, the level of $G\;{\alpha}i$ mRNA was significantly elevated during the butorphanol withdrawal. These results suggest that region-specific changes of G protein ${\alpha}-subunit$ mRNA were involved in the withdrawal from morphine and butorphanol.

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A Study on the Management of Fisheries Cooperative in Korea (한국수협운영의 문제점과 대책방향)

  • 김경호
    • The Journal of Fisheries Business Administration
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    • v.26 no.2
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    • pp.27-52
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    • 1995
  • I have outlined the history of Korean Fisheries Co - coperatives and its economic and noneconomic contribution to Korean Fisheries. But in order to overcome new economic world trend that is emerging now with the beginning of the WTO Korean Fisheries Co - operatives should change itself. It can be summarlized as follows. (1) The early Korean Fisheries Co - operatives was monopolized by Japanese under the Japanese colonial rule. (2) The modern Korean Fisheries Co - operatives was organized in 1962. 4. 1 by Korean government. (3) Korean Fisheries Co - operatives was weak in democratic management because of socioeconomic bad condition. (4) In spite of the dependence on the government financial aid Korean Fisheries Co - operatives has contributed to the fisheries development. (5) At the aid of the credit undertaking economic project was enlarged greatly, (6) With the close of the UR talks we cannot but open out fisheries market. So we are in condition that must enforce out fisheries compatability. especially, \circled1 Improvement of fisheries structure to enlarge management scale \circled2 Increase of productivity in fishing ground \circled3 The continuous endeavour to positive marine resourses making (7) Reorganization of fisheries, for example fisheries system or fisheries structure (8) Reexamination of the organization and operation of Korean Fisheries Co - operatives. And taking a proper step to improve their weak points. (9) The strengthening of the activity of investigation and study in centural Fisheries Co - operatives (10) It needs a special study to establish a few target or object in the management of Fisheries Co - operatives. When we could solve these ones mentioned above our fisheries will develop again.

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The Sublimation Pressure and Standard Enthalpy of Sublimation of Bismuth Triiodide ($BiI_3$에 대한 승화압과 승화 표준 엔탈피)

  • 김준학
    • Journal of the Korean Ceramic Society
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    • v.27 no.7
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    • pp.943-951
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    • 1990
  • Steady-state sublimation vapour pressures of anhydrous bismuth triiodide have been measured by the continuous gravimetric Kundsen-effusion method from 430.0 to 558.9 K and equilibrium sublimation pressures were obtained from the steady-state data. Condensation coefficients and their temperature dependence have been derived from the effusiion measurement. Condensation coefficients ranged from 0.159 to 0.048(475 to 500K), the activation enthalpy and entropy for condensation have been obtained as -93.38kTmol-1 and -212.70JK-1mol-1. The standard sublimation enthalpy changes derived by both second(modified sigma function) and third(average enthalpy method) law methods were 138.261$\pm$0.023, 138.74$\pm$0.002kJmol-1 respectively. The standard sublimation entropy change derived by modified sigma function was 191.98$\pm$0.047 JK-1mol-1. The reliable standard sublimation enthalpy change based on a correlation of ΔgcrHom(298.15K) and ΔgcrSom(298.15K), a recommended p(T) equation has been obtained for BiI3(cr) ; 1g(p/Pa)=-C/(T/K)+5.0711g(T/K)-2.838$\times$10-3(T/K)-7.758$\times$103(K/T)2+1.4519 where p is in Pa, T in Kelvin, ΔgcrHom(298.15K) in kJmol-1 and C=(ΔgcrHom(298.15K)-8.7358)/1.9146$\times$10-2.

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Experimental analysis of an asymmetric reinforced concrete bridge under vehicular loads

  • Thambiratnam, D.P.;Brameld, G.H.;Memory, T.J.
    • Structural Engineering and Mechanics
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    • v.9 no.1
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    • pp.17-35
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    • 2000
  • Dynamic response of a three span continuous bridge has been determined by full scale experiments on the bridge. In the experiments, a heavy vehicle was driven across the bridge at different speeds and along different lanes of travel and the strains were recorded at different locations. The bridge was made of reinforced concrete and was asymmetric in plan and in elevation. Frequencies and modes of vibration excited by the vehicle were determined. The dependence of the dynamic amplification on bridge location and vehicle speed was investigated and dynamic amplifications up to 1.5 were recorded, which was higher than values predicted by bridge design codes. It was evident that when this asymmetric bridge was loaded by an asymmetric forcing function, higher modes, which are lateral and/or torsional in nature, were excited. Dynamic modulus of elasticity and the support stiffness influenced the natural frequencies of the bridge, which in turn influenced the dynamic amplifications. Larger than anticipated dynamic amplification factors and the excitation of lateral and/or torsional modes should be of interest and concern to bridge engineers.

A Study of Behavior Based Authentication Using Touch Dynamics and Application Usage on Android (안드로이드에서 앱 사용과 터치 정보를 이용한 행위 기반 사용자 인증 기술 연구)

  • Kim, Minwoo;Kim, Seungyeon;Kwon, Taekyoung
    • Journal of the Korea Institute of Information Security & Cryptology
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    • v.27 no.2
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    • pp.361-371
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    • 2017
  • The increase in user data stored in the device implies the increase in threats of users' sensitive data. Currently, smartphone authentication mechanisms such as Pattern Lock, fingerprint recognition are widely used. Although, there exist disadvantages of inconvenience use and dependence that users need to depend on their own memory. User behavior based authentication mechanism have advantages of high convenience by offering continuous authentication when using the mobile device. However, these mechanisms show limitations on low accuracy of authentication and there are researches to improve the accuracy. This paper proposes improved authentication mechanism that uses user's smartphone application usage pattern which has not considered on earlier studies. Also, we analyze performance of proposed mechanism with collected datasets from actual use of smartphone applications.

Spontaneously Adsorbed Mo Layers on Pt(111) and Pt(100) Single Crystal Electrode Surfaces

  • Han, Yoon-gu;Jung, Chang-hoon;Rhee, Choong-Kyun
    • Bulletin of the Korean Chemical Society
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    • v.23 no.3
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    • pp.395-399
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    • 2002
  • The voltammetric behavior of spontaneously adsorbing Mo layers on Pt(111) and Pt(100) electrodes has been studied to estimate the number of electrons involved in the electrochemical processes of spontaneously adsorbed Mo and the number of the bloc ked Pt sites for hydrogen adsorption. On Pt(111) and Pt(100) surfaces, the spontaneously adsorbed Mo layers showed redox peaks at 0.10 V and 0.15 V, respectively, and continuous current-potential waves in the conventional hydrogen region. Since the potential range of the Mo redox processes on both surfaces overlapped partially with the potential range of hydrogen adsorption, the variation in the ratio of the total charge of Mo and H ($Q_H$ +$Q_{MO}$) to the hydrogen charge of clean Pt electrode ($Q_H^0$) was analyzed. From the analysis, six electrons were estimated to be involved in the electrochemical processes of the spontaneously adsorbed Mo, and four Pt sites for hydrogen adsorption were calculated to be blocked by one adsorbed Mo atom. Based on these figures and the pH dependence of the Mo redox processes, we have proposed an electrochemical equation for the spontaneously adsorbed Mo. This electrochemical equation led us to conclude that the saturation coverage of the spontaneously adsorbed Mo is 0.25. The coverage of Mo less than 0.25, however, could not be determined voltammetrically due to the convolution of the charges of Mo and H.

Exponent Study of the p($2{\times}1$) Phase on an O/W(110) Surface (O/W(110) 표면의 p($2{\times}1$) 구조의 임계지수 연구)

  • 백두현;정석민;정진욱
    • Journal of the Korean Vacuum Society
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    • v.1 no.1
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    • pp.88-95
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    • 1992
  • Abstract-Using a high resolution low energy electron diffraction(HRLEED), we report an exponent study of 2d continuous phase transition from an ordered ~ ( 2 x 1 )ox ygen overlayer on a W(110) surface. Temperature dependence of a (% 0) superlattice diffraction spot, characteristic of the p(2X 1) structure, shows power-law like divergence of the susceptibility and the fluctuation correlation length at T,=708.765 K. By fitting the intensities as well as the line-shapes, we obtained exponents P=0.19* 0.05, y=1.48+ 0.34, v= 1.23i 0.27 and q=0.38+ 0.12. The non-universal character of the exponents are understood in terms of a 2d XY model with cubic anisotropy as suggested previously.

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